Trying to recover 2-element zfs striped (raid0) filesystem

[Kirk Richard Holz]

Thanks for the help, just a query here, what does the 8683733800792668130 number signify in the zpool / zshare on the UNAVAIL line of the list, I’ve quoted below? It doesn’t look like a UUID as it appears to be decimal not hex. I haven’t written to the drives and I’m cloning them now.


>        NAME                   STATE     READ WRITE CKSUM
>        zShare                 UNAVAIL      0     0     0
>          ada1                 ONLINE       0     0     0
>          8683733800792668130  UNAVAIL      0     0     0  was /dev/ada3s1
> 

On 27/07/2013, at 06:01 , Peter Jeremy <peter at rulingia.com> wrote:

> On 2013-Jul-26 01:33:01 -0700, Kirk Richard Holz <krh at kirkholz.com.au> wrote:
>> The partition table of one of the two disks in a zfs striped (raid0) 
>> array has been corrupted.
> 
> Once you recover the partition table for ada3, ZFS should be OK (as
> long as you haven't written too much to the pool).  If zShare is your
> boot device, I strongly recommend booting off alternative media.
> Ideally, you should take full physical copies of both disks.
> 
> If you are unable to remember the partition layout, you should be able
> to recover it by looking for the ZFS vdev labels:  Each ZFS vdev has
> 4 256KiB labels - 2 at the start of the partition and 2 at the end of
> the partition so locating those will identify the start and end of the
> partition - if you used the entire disk for ZFS, they will be close
> to the start & end of the disk and "hd /dev/ada3|less" should be
> enough to find the first label.  The first label on all my vdevs begins:
> 
> 00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
> *
> 00003fd0  00 00 00 00 00 00 00 00  11 7a 0c b1 7a da 10 02  |.........z..z...|
> 00003fe0  3f 2a 6e 7f 80 8f f4 97  fc ce aa 58 16 9f 90 af  |?*n........X....|
> 00003ff0  8b b4 6d ff 57 ea d1 cb  ab 5f 46 0d db 92 c6 6e  |..m.W...._F....n|
> 00004000  01 01 00 00 00 00 00 00  00 00 00 01 00 00 00 24  |...............$|
> 00004010  00 00 00 20 00 00 00 07  76 65 72 73 69 6f 6e 00  |... ....version.|
> 00004020  00 00 00 08 00 00 00 01  00 00 00 00 00 00 13 88  |................|
> 00004030  00 00 00 24 00 00 00 20  00 00 00 04 6e 61 6d 65  |...$... ....name|
> 
> If you look at the output of "zdb -C zShare", the 'asize' value is the
> usable size of the vdev in bytes - the physical size is a slightly
> larger (~4.5MB for me) but the labels are at the end of the physical
> partition.
> 
> For more details, see the ZFS On-Disk Specification (ondiskformat0822.pdf)
> 
> -- 
> Peter Jeremy